The demand for electronic communication of data has exploded in recent years. A variety of technologies have been developed to meet this demand. These technologies deliver data at ever increasing speeds. One technology for delivering data is referred to as digital subscriber line (DSL) technology. DSL technology encompasses a variety of technologies including but not limited to asymmetric digital subscriber line (ADSL), symmetric digital subscriber line (SDSL) including G.SHDSL, high bit rate digital subscriber line (HDSL), very high bit rate digital subscriber line (VHDSL), and rate adaptive digital subscriber line (RDSL). In each case, DSL technology delivers high speed digital transmission over existing telephone lines, e.g., twisted copper pairs.
DSL technology typically communicates digital data between customer premises equipment (CPE) and a data network. The customer premises equipment is commonly includes a DSL modem or an integrated access device. The data network typically comprises an Asynchronous Transfer Mode (ATM) network or other appropriate data network. DSL technology uses a device known as a digital subscriber line access multiplexer (DSLAM) to facilitate the connection between the customer premises equipment and the data network.
The DSLAM is located, for example, at a central office of the telephone company. A conventional DSLAM includes a number of different cards or boards in a rack or housing. In one conventional approach, the DSLAM includes at least one line card that provides connection to the data network over one or more high capacity lines, e.g., an OC-3 line, a DS-3 line or other appropriate high capacity line. The DSLAM also includes a number of channel cards, e.g., cards that provide connection to a number of modems over a number of telephone lines or twisted pairs.
A data network typically includes a number of switches that are interconnected to provide a plurality of communication paths through the network. Further, customer premises equipment communicates over the network with an Internet service provider (ISP) that is connected to another switch in the network. To establish this connection, a soft permanent virtual connection (SPVC) is established through the network between the customer premises equipment and the ISP. This connection includes at least three parts. The first part is a permanent virtual connection (PVC) between the customer premises equipment and the DSLAM over a telephone line. The second part is a switched virtual circuit (SVC) between DSLAM and the switch connected to the ISP. Finally, another permanent virtual connection provides the final part of the connection between the switch and the ISP.
The switched virtual circuit between the DSLAM and the switch is established using any of a number of protocols. One protocol includes the private network-network interface (PNNI) protocol. This protocol provides dynamic routing of SVCs through the network and is based on the open shortest path first (OSPF) protocol. PNNI allows routing to change dynamically based on current conditions in the network. However, the PNNI protocol is complicated and expensive and time consuming to implement. An alternative to PNNI is the interim inter-switch signaling protocol (IISP). IISP uses a static routing protocol that requires manual configuration of the routes through the network. However, IISP does not provide a mechanism for communicating the information necessary to establish the PVC at the switch connected to the ISP to provide end-to-end connectivity. Therefore, there is a need for improvements in establishing end-to-end connections between an ISP and customer premises equipment.